Anchor bolt casing



May 29, 1934. E. c. CANNON ANCHOR BOLT CASING Filed June 5, 1931 lNVENTOR WITNESSES Patented May 29, 1934 PATENT OFFICE ANCHOR BOLT CASING Edgar C. Cannon, Donora, Pa.

Application June 3, 1931, Serial No. 541,909

1 Claim.

This invention relates generally to anchor bolts set in concrete, and more particularly to casings adapted to space a free portion of a bolt from the surrounding concrete.

In construction work involving erecting steel superstructures upon concrete foundations, or setting machinery and the like upon concrete bases, anchor bolts are generally used to secure the one to the other. These bolts are set in the concrete with a threaded end projecting far enough above the surface to pass through holes in the base of the structure which is to rest upon the foundation. However, when the metal structure is ready to be bolted in place, it is often found that the bolts in the concrete and the holes in the structure do not register exactly. This may be due to several reasons, including shifting of the template, slight springing of the forms, the bolts not being held plumb or being moved out of plumb by concrete pouring into the forms, and irregularities in the spacing of the holes in the structures that are to be placed over the bolts.

To overcome this difiiculty it is customary to provide a casing to encircle the top of the bolt for some distance down into the concrete, in order to keep the concrete away from that portion of the bolt, so that there will be a surrounding space in which it can be bent laterally to bring it into proper position to engage its hole in the superstructure.

The lower portion of the bolt is firmly set in the concrete. Such casings are often makeshift devices consisting of a short section of stove pipe, 2, tin can or the like, held in place around the bolt by means of wires, nails, props, or anything else that is handy at the time. No means for centering the bolt relative to such casings is provided, and they are therefore apt to be wired haphazardly to hold them in place. Be-

sides, it is necessary to provide a closure for the bottom of the casing to prevent the concrete from coming up into it.

It is among the objects of this invention to pro- 'vide an anchor bolt casing or shell of simple construction and a minimum of parts adapted to rapid and accurate centering and holding of the bolt in adjusted position therein, which can not be shifted relative to the template after once being secured thereto, and can be easily removed from the concrete after it has hardened.

In the accompanying drawing Fig. 1 is a plan view of the casing or shell embodying my invention showing optional means for centering the bolt therein; Fig. 2 is a side elevation thereof;

and Fig. 3 is a vertical longitudinal section of the casing with the bolt disposed therein, both set in a concrete foundation and secured to a template resting on top of the casing.

The construction embodying my invention comprises a metallic casing or shell in the form of a frustrum of a cone the truncated end of which is adapted to slidably fit around an anchor bolt, means at the outer end of the cone for securing it to a template, and means for positioning the bolt in the casing.

Referring to the drawing, a metallic frustrum of a cone 1, preferably made of a single sheet of metal with its joining edges crimped or soldered together, has an opening 2 at its truncated end to accommodate an anchor bolt 3. The size of the opening is such that the bolt will fit therein snugly but slidably so that a closure for the lower end of the casing is unnecessary. The upper or outer end of the cone is provided with a pair of oppositely disposed integral ears or flaps 4 having holes 5 therethrough in which wires or nails 6 are inserted to secure the casing to a template '7.

corresponding in position to similar holes in the base of the structure which is to rest upon the concrete foundation 9. In order to insure that the outer edge of the cone, when fastened to the template, will be equidistant from guide-hole 8 in the template, a single piece of wire 10 is passed through two pairs of oppositely disposed holes 11 in the wall of the cone near its outer end, the two lengths crossing the cone forming loop 12 through which the upper end of the bolt passes. The free ends of the wire are brought together outside the cone and can be twisted to tighten loop 12 around the bolt to hold it securely in the center of the casing. The casing is of such length relative to the length of the bolt as to leave a sufiicient portion of the bolt free to be embedded in the concrete.

In using this casing, an anchor bolt is passed through opening 2 in the casing and on through loop 12 in the wire. While the bolt is held in the center of the casing, the free ends of the wire are twisted together to tighten the loop around it so that it will stay in central position. This wire loop also serves to hold the bolt in desired longitudinal adjustment with respect to the template, and consequently to regulate the depth of the bolt in the concrete. The outer end of the casing is then placed against the template withthe end of the bolt projecting through hole 3. As the bolt has been held in the center of the casing by means of loop 12, it follows that when the outer end of the casing is placed in contact with the template it will be equidistant from hole 8, and the bolt will be perpendicular to the template.

The casing is then secured to the template in this position by means of nails inserted in the holes in lugs 4 and driven into the template. In most cases it will be found to be easier to secure the casing in place if the template is turned bottom side up and the casing nailed downwardly to it While in that position.

When the casing is in place, the template, carrying it and the bolt, is put in position and the concrete poured into the forms. The lower unencased portion of the bolt will beembedded in the concrete but the upper portion will be left free. After the concrete has hardened the template is removed and the casing due to its conical shape, may also be removed, particularly if the outside has been greased before pouring the concrete. Then if for any reason it is found that the bolt does not register with the hole in the structure to be mounted on the concrete, it can be bent laterally in any direction within the limits of the conical space 13 formed in the concrete by the casing.

According to the provisions of the patent statutes, I have explained the principle and mode of operation of my invention, and have illustrated and described what I now consider to represent its best embodiment. However, I desire to have it understood that, within the scope of the appended. claim, the invention may be practiced otherwise than as specifically illustrated and described.

I claim:

- In combination with an anchor bolt adapted to be set in concrete with one end projecting therefrom, and a template adapted to form the surface of the concrete and to position the bolt, a metallic frustrum of a cone the truncated end of which is adapted to slidably fit the bolt, ears at the outer end of the cone for securing it to a template resting thereon, and a cross-looped wire extending through the sides and across the outer end of the cone for holding the bolt in position in the shell.

EDGAR C. CANNON. 

